There's clearly some synergy between TV and social platforms like Twitter -- but what's big on television is not always what gets the most chatter online.

Unsurprisingly, major events drove the most TV-related tweets and engagement, according to Nielsen analysis of Twitter activity for the 2013-14 TV season. Super Bowl XLVIII on Fox scored as the most social TV event across all program types with 15.3 million people seeing a total of 1.8 billion tweets about the game and halftime show.

Consider that CBS had five of the top 10 broadcast shows for the 2013-14 season, per Nielsen ("The Big Bang Theory," "NCIS," "NCIS: Los Angeles," "Person of Interest" and "Blue Bloods") -- but none of those were among the top 10 most-tweeted shows.

AMC's "Breaking Bad" set the record for Twitter reach of a single airing of a primetime show, with 9.1 million people seeing tweets during the finale, and the Bryan Cranston-starrer was No. 1 with an average Twitter audience of 6.0 million.

Why is CBS big on TV but not Twitter? Simple demographics explain a lot: CBS still has the oldest audience among broadcasters with a median viewer age of 58. And older people use Twitter less. Just 9% of Americans 50-64 and 5% of those 65 and older used Twitter in 2013, compared to 31% of those 18-29 and 19% of those 30-49 according to Pew Research Center.

Meanwhile, certain shows have been built with Twitter in mind. "The Voice" on NBC set a record for most tweets during a telecast, with 1.92 million posted during the May 13 airing, according to Nielsen. The driver: The show prompted viewers to tweet #VoiceSave to rescue their favorite contestant; the hashtag was included in 1.5 million tweets.